function changeBulb() 
{
	var bulb = document.getElementById('bulb');
	
	if(bulb.src.match('bulboff.gif'))
	{
		bulb.src = 'imgs-bulb/pic_bulbon.gif';
	} else {
		bulb.src = 'imgs-bulb/pic_bulboff.gif';
	}
	
}